The 53-year-old Virginia resident was fatally injured by his own lance at an event in Williamstown, Kentucky, while competing in an equestrian game, NBC Washington reports.

His brother, John Barclay, said in a Facebook post that the accident happened when Barclay’s metal-tipped lance, which was not used for jousting, “hit the ground and flipped,” fatally impaling him under the sternum in a “freak accident,” the Louisville Courier-Journal reports.

Barclay had been taking part in a competition that involved picking a paper plate off the ground with the 7-foot lance.

The SCA, which has more than 30,000 members and specializes in recreating medieval warfare, says it is investigating the accident. Society president John Fulton tells the Washington Post that Barclay—a recently retired Army lieutenant colonel—was a “consummate expert” and active member of the group who had been taking part in similar events for more than 30 years.

“He knew how to do it and how to do it safely.” Barclay, he says, was wearing a doublet instead of full body armor because there were no other riders in the ring. In the accident, Fulton says, “something happened with that spear, and he lost control of it or it turned, hit the ground, and as his horse was moving, the tip of it went into him.” He adds: “It is a horrible set of circumstances that caused this.”